Re: [Gimp-print-devel] More stuff

[Ron v. O. <R.A...@Wb...>]

Robert L Krawitz wrote:
> 
>    Date: Thu, 04 May 2000 12:57:49 +0200
>    From: Ron van Ostayen <R.A...@Wb...>
> 
>    Robert L Krawitz wrote:
> 
>    > There are some bug fixes for the ESC 440 (so it should finally do
>    > softweave correctly), and another bug fix for 360 dpi mode that may
>    > improve performance on the ESC 900.  I've also incorporated
>    > Jean-Marc's new ink constants for the ESP 870.
> 
>    I've tested this on my ESC900.
>    The 360dpi mode is a bit faster and the floating point exception is
>    removed.
> 
> OK.  But it's still somewhat slower than the Windows driver?

Yes.  See below.

> 
>    Is this a 2-pass mode or 1-pass?  I believe the windows driver is
>    1-pass.
> 
>    Is this a bi-directional printing mode?  I suspect it is uni-directional
>    and i think it could/should be bi-directional.
> 
> One pass, and bidirectional.

Now I'm confused.  The printer head goes across the page dumping ink,
and returns dumping ink.  Then the paper is moved forward approx. 1.4cm.

I would call this 2-pass, bidirectional?

The windows driver uses a mixed approach:  When color is needed it uses
the same approach as gimp-print but when (black) text or figures are
printed then the head goes across the page dumping ink, the
paper is moved forward 1.4cm, the head returns dumping ink, and the
paper is moved forward approx. 1.4cm.

I would call this 1-pass, bidirectional?

Furthermore the windows driver uses a much faster method of paper
transport across empty areas.  The gimp-print driver is very slow across
empty areas.

As a consequence, the gimp-driver is still about 2x slower during
printing than the
windows driver.  

And yet the windows printer dump file size is about 2x as large.

During rendering the difference is a more pronounced: Printing 10 pages
of my report to file takes about 20s in windows and 220s in gimp-print!!

Printing to paper of the windows printer dump file in linux takes about
80s.
Printing to paper of the gimp-print printer dump file in linux takes
about 150s.

The quality of in particular the windows text is much better than the
gimp-print output.  Figures and photos are comparable.

> 
>    However some errors occur in the other quality settings.
> 
>    Quality   Time(s)  FileSize     Printing time (time cat tiger0..9.prn >
>    /dev/lp0)
>      0        33.2     1986522       18.5  OK but top margin is approx
>    0.9cm smaller than for other settings.
>      1       112.1     7118815       68.0  OK
>      2       110.6     7118808       error in output (empty pages and
>    garbage)
>      3       116.1         955 !!
>      4      signal 11
>      5       191.5     9977020      121.0  OK
>      6       190.2         605 !!
>      7       198.7        2042 !!
>      8       356.4        2127 !!
>      9       390.9        1549 !!
> 
>    I have succesfully tested 3.1.3 with quality setting 0,1,2,3,5,6 and 8
>    so the last changes seem to have broken some settings.
> 
> Basically, all the softweave modes are shot by the look of it.  It's
> not obvious to me why that is the case right now...
> 

Ron van Ostayen

R.A...@Wb...
Laboratory of Tribology
Department of Mechanical Engineering
University of Technology Delft